1. Field of the Invention
This invention relates to fluid handling devices and, more particularly, to devices for delivering fluid at a controlled rate and for mixing fluids in a controlled ratio.
2. Description of the Prior Art
In many fields it is necessary to deliver a single fluid at a precisely controlled rate or to deliver a predetermined mixture of fluid at a controlled rate. Pumps presently in use for these purposes are relatively expensive and somewhat complex. A more important disadvantage of conventional pumps when used in certain fields, such as the medical field, is the difficulty of sterilizing or cleaning such pumps. For example, in the field of dialysis treatment for kidney disease, a concentrated dialysate solution is mixed with water and dextrose before being directed to other dialysis equipment. It is extremely important that such equipment be sterile since the mixed dialysate can carry germs and infections to the patient, particularly during a peritoneal dialysis treatment. The medical field has generally solved the sterilization problem to a large extent by utilizing disposable, presterilized devices. However, it has not been possible to solve the sterilization problem of conventional dialysis pumps in this manner because their relatively high expense makes disposal after each use financially impractical.